In the currently produced paints, the binders consist of synthetic polymer resins with extremely long and complex molecules. The polymerisation time of a normal synthetic resin and hence of the film of paint is about 3 weeks. During this period, solvents, bactericides and surfactants which are extremely dangerous for human health and which, in particular in water-based paints--being odourless--manage to produce the most harmful effect, are released into the atmosphere. The gravity of this state of affairs is confirmed by modern medical science which is now universally in agreement in attributing to paints in general, and to drying agents in particular, many of the causes of serious pathological conditions. Of these, different types of tumour, acute allergies, asma, bone disorders, etc., are so recurrent among manufacturers and users of these paints that they are now regarded as professional illnesses true and proper within the sector.
Another disadvantage of these resins consists in the fact that the film formed after drying, although resistant and elastic, with time tends to deteriorate, showing signs of cracking, peeling and crumbling which ruin the aesthetic appearance, adversely affecting the supporting materials and producing dangerous dusts which are inhaled by the occupants of the environment.
The second group of components consists, as mentioned, of pigments. At present the pigments used are of the artificial inorganic type and consist of iron and zinc oxides, and titanium dioxides or organic pigments derived from oil.
All these substances have the disadvantage that they represent a source of environmental pollution.
The third group, finally, consists of fillers, the choice and dosing of which significantly influences the amalgam between binders and pigments, thus also making the paint more resistant, if carefully chosen and suitably dosed.
The most important components of the fillers currently used are natural substances such as (amorphous and crystalline) calcium carbonate, calcites, talcs, gypsum, sand, quarzites, etc. However, nowadays the tendancy to use artificial fillers comprising powders which are coated, calcites, talcs, gypsum, sand, quarzites, etc. However, nowadays the tendancy to use artificial fillers comprising powders which are coated, precipitated or have a completely synthetic structure is becoming increasingly widespread.
Finally, as regards the secondary components, in this case also, the tendancy to use toxic synthetic chemical additives has now become widespread.
A paint composition of the type described in prior art portion of claim 1 (WPI Dervent 81-79092D[43] & SU-A-800154) is known in which the paint comprises in combination:
pigments in liquid solution chosen from the group of naturally colouring earth; PA1 binders chosen from the group of milk, casein, starch paste and potato flour; PA1 compounds, mixed with said pigments and binders, chosen from the group of borax, kalinite, calcite, kaolin, slaked lime, mica and talc, sea salt and boron salts; PA1 additives chosen among groups of substances of natural origin.
With a paint of this kind considerable drawbacks are caused by using of drying oil. The casein implies an acid environment, this favours bacteria proliferation and chemical reaction with calcium carbonate, which further causes color alterations. Therefore, to avoid these problems the paint needs an high quantity of the drying oil is added.
If the quantity of the drying oil is instead low, and the paint is applied on walls with humidity, the humidity tends with time to deteriorate the film formed after paint drying, showing signs of cracking, peeling and crumbling. A percentage of boiled linseed oil (more than 2-3%) darkens the paint.
The drying oil is however obtained only with double boiling process with lead and/or other heavy metals, and by using also additives as naphthenes or similar compounds derived from oil cracking. All these materials used during the driving process are health dangerous and no compatible with ecological environment.
In accordance with the invention, these problems are resolved by means of a paint in which all the components, i.e. pigments, binders, fillers and additives, are chosen in combination with each other from substances and products which can be easily found in nature and are such as to cause a minimum impact on the ecosystem.